Abrasive disk



Aug- 29, 1933. A. J. DOERMANN -1,924,773

ABRASIVE DISK Filed March 11, 1932l 2 Sheets-Sheet l ZZ@ g I Au8- 29, 1933- A. J. Dox-:RMANN 1,924,773

ABRAS IVE DISK Filed March 11, 1932 2 Sheelzs-Sheei'l 2 Patented Aug. 29, 1933 l 1,924,773 ABRAsIvE DISK Albert J. Doermann, Chicago, Ill., assgnor to Titan Abrasives Company, Chicago, Ill., a corporation of Illinois Application March 11, 1932. Serial No. 598,278

3-Claims. (Cl. 51-209) This invention relates to improvements in abrasive disks and, more especially, such a disk employing a sheet metal back. The invention is applicable to such a disk made in segments or in one piece. Y

Among the features of my invention is the provision of such a disk with a metal back that can be made out of relatively thin sheet metal, thus cutting down the cost of manufacture and the l0 weight of the disk.

Improved means are provided for attaching the disk to the face-plate of the grinding machine. When a relatively thin piece of metal is employed for making the back, diiiculty has been encountered in attaching the same to the steel plate of the grinding machine. This difficulty is overcome in the practice of my invention in a manner to be hereinafter set out.

Other features and advantages of my invention will appear more fully as I proceed with my specification. l

In those forms of devices embodying the features of my invention shown in the accompanying drawings'- Figure 1 is a top plan View with' portions of the abrasive coating removed; Fig. 2 is a view taken as indicated by the line 2 of Fig. 1; Fig. 3 is a top plan view of one of the back segments; Fig. 4 is a similar view of one of the washers; Fig. 5 is a view similar to Fig. 2 showing the mold in which the disk is formed; and Fig. 6 is a view similar to Fig. 1 showing a one-piece disk instead of a segmental disk.

As shown in the drawings, the device of Figs. 1 to 5, inclusive, is made up of eight segments. Each of these segments is entirely separate and distinct and provided with its own back. One of these backs is shown in Fig. 3. The back segments are preferably pressed, stamped or formed out of relatively thin sheet metal. The back segment is indicated by 10. This segment is provided with a low peripheral upstanding rim 11.

Each back segment is provided With'a plurality (here shown as six) of holes 12 each surrounded byv a circular upstanding ridge 13. The ridges 13 may be connected by a network of upstanding ridges 14 to add stiffness and strength to the back. Likewise, there may be provided short additional ridges or corrugations 15 for the same purpose. Each of the ridges 13 is sufficiently removed from the hole 12 to provide a circular at area 16 surrounding the hole 12 to accommodate a washer to be hereinafter described. In effect, therefore, it may be stated that the circular area 16 is in the nature of a depression, considering the ridge 13 that surrounds it.

In Fig. 4 is shown a washer 17. One of these is placed inregistry with each of the holes 12. This washer is preferably stamped, pressed or formed out of sheet metal and is provided with an upstanding circular rib or corrugation 17a around its hole. In Fig. 5 I have shown a mold in which the segments are cast. This mold has a base Y18 with aperipheral upstanding flange or rim/19 65 and is shaped to t the segment 10. The segment is placed in the mold, as shown in Fig. 5, and the Washer 17 laid in registry with the holes 12. The base 18 of the mold' is provided with threaded holes 20 adapted to accommodate the 70 reduced threaded ends 21 of plugs 22 that are screwed in through the holes 12 in the back segments. These plugs hold the washers in place and also serve to form holes in the abrasive disk to accommodate the fastening devices used for 75 attaching the disk to the face-plate of the grinding machine for use. When the back is in place in the mold, as shown in Fig. 5, and the plugs 22 installed, the abrasive coating is placed on the back in the usual manner. For example, there may be applied to the face of the back, first a thin coating of cement 23 and then a. coating of abrasive material 24, for example, siliconof carbide with a suitable binder or cement. After the abrasive coating has been baked or otherwise hardened, the plugs 22 are removed and the abrasive disk, or segment, lifted out of the mold. The removal of the plugs 22 leaves holes 22a in the abrasive disk that will accommodate machine screws or other fastening de- 9,0 vices 25 .for attaching the completed disk or segment to the face-plate 26 of a grinding machine.

As stated above, the disk may be made in one piece or in segments. In Fig. 6 I have shown a 95 one-piece disk in which the steel back is indicated by 110 instead of 10 the rim by 111 instead of. 11, and the holes by 1 2 instead of 12. The coating on this back is indicated by 124 instead of 24 and the holes therein 122a are for the purpose of 100 accommodating fastening devices to attach the disk to the steel back of a grinding machine. In other respects, the construction and operation of a one-piece disk are similar to the multisegment disk above described.

The Washers 17 with the circular ribs 17EL surv rounding their holes serve to strengthen the back where the fastening devices 25.are put through and the ribs especially serve to strengthen the construction and add rigidity to the attachment. 110

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention asdiselosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as permissible, in view of the prior art.

What I regard as new, and desire to secure by Letters Patent, is:

1. An abrasive disk, comprising; a sheet metal back with a plurality of holes each surrounded ALBERT J. DOERMANN. 

